Philadelphia - The Electronic Frontier Foundation (EFF) urged a U.S. appeals court Monday to block the government's repeated attempts to seize cell phone location information -- a record of where the cell phone user travels throughout each day -- without a warrant in violation of communications privacy statutes and the Constitution.

In September of last year, a federal court affirmed that location information stored by a mobile phone provider is legally protected and that a judge can and should require law enforcement to show probable cause in order to access the stored data. However, the government appealed that decision to the 3rd U.S. Circuit Court of Appeals.

Cell phone providers store an extraordinary amount of data about where you are when making or receiving a call, based on the cell towers your phone uses. In the amicus brief filed Monday, EFF argues that Electronic Communications Privacy Act and the Fourth Amendment protect this location information from unfettered search and seizure.

"The government argues that federal law requires judges to approve their applications for location information from cell phone companies -- even if the police don't have probable cause to obtain this sensitive information," said EFF Civil Liberties Director Jennifer Granick. "Courts have the right under statute -- and the duty under the Constitution -- to demand that the government obtain a search warrant before seizing this private location data."

The American Civil Liberties Union (ACLU), the ACLU Foundation of Pennsylvania, and the Center for Democracy and Technology (CDT) joined EFF's brief.

For the full amicus brief:
http://www.eff.org/files/filenode/celltracking/Filed%20Cell%20Tracking%20Brief.pdf

For more on cell phone tracking:
http://www.eff.org/issues/cell-tracking